Insulating composition.



V and "UNITED STATES PATENT OFFICE.

JONAS W. .AYLSWOBTE, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO CONDENSITECOKPAINY OFLIERICA, OF GLEN RID GE, NEW JERSEY, A CORPORATION OF NEWPatented July 7, 1914.

JERSEY. J

' INSULATING COMPOSITION.

1,102,633, Specification of Letters Patent.

No Drawing. Application filed January 2, 1912. Serial No. 668,941.

To all whom it may concern:

Be it known that I, J ONAB W.AY1'.swoR'rn, a citizen of the UnitedStates, and a res1- dent of East Orange, in the county of Essex andState of New Jersey, have invented certain new and useful Improvementsin Insulating Compositions, of which the following is a description. Myinvention relates to a composition of matter which shall be valuable asa cement or sealing compound for electrical apparatus and also as aninsulating impregnating compound for coils and the like.

Accordingly, my object is to produce such a composition having thevaluable properties which will be hereinafter pointed out.

Referring more particularly to the composition when used as a sealingcompound or cement for electrical apparatus, such as transformers,coils, conduits and other electrical-appliances, it is particularlydesirable that the composition should have a high flow point andcongealing-poi nt so that the compound will not become dislodged whenthe apparatus sealed thereby becomes heated in use. It is alsodesirablethat the composition should have high dielectric strength goodmechanical strength, strong adhesion to the object which it is desiredto cement or seal and to be oil and water proof and non-corrosive. Thecomposition should also be extremely fluid when molten so that'it canreadily be poured and flow into the spaces to be filled thereby when theapparatusis in place and so that itmay be heavily loaded with fillingmaterials when desired. It should also have only a small shrinkage whencooling and solidifying in osition. The compositions describedheremafterfulfil these requirements to a marked degree. The greatfluidity and other properties of thehereinafter described compositions,make themalso especially valuable as impregnating compounds for coils.Some of the hereinafter described composit ons also have the desirableproperty of being somewhat flexible when cold.

The composition comprises a fusible nat ural or synthetic gum,compounded with a non-volatile crystalloid substance of high melting.point which shall have the property of giving the substance a more orless sharp setting point at a comparatively elevated temperature and theproperty of being thmly fluidwhenmolten. Such gums re ferred to, arenatural varnish gums, such as copal, shellac, Manila gum, and kauri orfusible synthetic, gums'such as phenol resins, WhlCh I may also class asvarnish gums.

-Also preferably, an oily substance, such as castor oil, a fluid cresol,or mono-chloronaphthalene, is included in the composition,

this oil being added for the purpose of rendering the compositionsomewhat flexible when cold and less brittle than it would otherwise be.To the composition may be added various quantities of powdered orfibrous mineral fillers, such as asbestos powder, mica, infusorialearth, clay, zinc oxid or the like. .The organic fillers, such as woodflour, may be used in some cases, but are not so desirable when the massis a high melting point composition. The ingredients of the composition,other than the filler, apparently form a solidified solution intermixedwith crystals of the crystalloid substance The gum or resin to be usedshould'be proof against such hydro-carb0n oils as are used forlubricating purposes and commonlyas oil seals for electrical apparatus,and also should be fusible non-conducting substances. all thosementioned being of this class. All those mentioned, however, are veryviscous when molten and none of them has a sharp setting point whichmakes them undesirable, alone, for the purposes of this invention. Myinvention consists chiefly in compounding with such agum, an insulatingsubstance having a high melting point and very slight solubility inhydro-carbon oils and insolubility in water, and which shall impart tothe composition the desired fluidity. when molten and a sharpercongealing point.

comparatively few available substances have these desirable qualities.Those which I have found suitable are cry'stalloids, such as phthalimidiphenyl phthalimid, "per chloro-naphtha one, andtetra;chloro-phenylene-oxid. Phenyl phthalimid is the preferredsubstance. having the desired characteristics. Phthalimid may be usedbut is not quite'as desirable as phenyl phthalimid because it has asomewhat lower boiling point. I A composition formed with phthalimidcannotv be heated above 360 without considerable loss by vaporization.The composition containing henyl phthalimld, however, may be heate toover 400 F. without much loss by vaporizing. Phenyl phthalimid ouum ggcim is a condensation product of aniiin and phtha'lic anhydrid, andphthalimid,

is a product formed by passing dry ammonia over heated phthalicanhydrid. Perchloro-naphthalene, C Cl and tetra-chlorophenylene-oxid, CCLO, v are known substances. When any of the gums t resins mentioned aremelted with phenyl phthalimid, phthalimid or equivalent crystalloid,

- a solution is formed which is thinly fluid and which has a more orless sharp con ealing point varying with the percentage'o thecrystalloid in the composition.

The composition in its least complex form, comprises approximatelyManila gum or equivalent, 100 parts, and phenyl phthalimid .20 to parts,with or without mineral fillers. Such a composition is proof againsthydro-carbon oils extremely. fluid when molten and has a high congealingpoint which may be varied between 240 F. and 320 F. by varying theproportions of phenyl phthalimid. I I 1 Examples of other variations areas follows 100 parts of Manila gum 'or equivalent gum or resin, 10 to.30 parts castor oil or equivalent oil, 20 to parts phenyl phthalimid orequivalentcrsytalloid, 0 to 100 parts of mineral filler.

100-,parts phenol ,resin, 10 to 30 parts cresol ormono-chloro-naphthalene, 20 to 70 parts phenyl phthalimid, 0 to 100parts filler. 7

100 parts shellac,120 to 60 parts phenyl phthalimid, 0 to 50 partsfiller. 1

The phenol resin referred to is preferably a fusible solublecondensation product of a phenol and formaldehyde having no uncombinedformaldehyde or otheringredient containing the methylene radical CH-therein. Such a phenol resin is described in my application Ser. No.-196,060, filed May 14,

'1909, and in my Patent No. 1,029,737 dated June-18, 19 12. Asstated,-the composition described may also with advantage be used as animpregnating compound for electrical coils. This is especially true whenthe compositionis formed with'copal or Manila gum. Ifphenol resin isused as the gum, in a composition intended for this purpose, the sameshould preferably be carefully dehydrated, and contain no free oruncombined phenol or only a-very slight percentage of the same. A phenolresin, such as described, can be completely dehydrated by subjecting thesame to a temperature of over 400 F. at atmospherlc pressure, as isdescribed inmy copending application and patent referred to, or byheating to a temperature approximately 50, F. less, in a vacuum.Suitable compositions for impregnating compounds are 4 i being thinlyfluid when molten, substantially as described. .o

2. An insulating composition comprising approximately 100 parts ofManila gum and 20 to 70" parts of phenyl phthalimid, substantially asdescribed.

I '95 3. An insulating composition which is slightly flexible when cold,has a congealing or setting point between 240 F. and 320 F., and isthinly fluid when molten, comprising a varnish gum, an oily substance,and

' a solid, non-volatile crystalline body, substantially as described.

4;..An insulating composition comprising a fusible varnish gum,'acrystalline body of high melting point and slight solubility inhydro-carbon oil and insoluble in water, and

a substance for imparting flexibility to the composition when cold,substantially as described.

5. An insulating composition comprising substantially parts of Manilagum, 20 to 70 parts of phenyl phthalimid, and from 10 to 30 parts ofcastor, oil, substantially as described.

6. A new composition of matter comprising a non-conducting fusible gumwhich is proof against hydrocarbon oils used for lubricating purposes,and a crystalline body' having a high melting point and slightsolubility in hydrocarbon oil or water, substantially as described.

7. An insulating composition comprising a varnish gum and phenylphthalimid, substantially as described. I

8. A new composition of matter comprising a hydro-carbon-oil proof gum,a crystalline body of high melting point and only slight solubility inhydro-carbon oil or wator, and a non-hydro-carbon oil, substandro-carbonoil or water, and a non-hydrotially as described. carbon oil',substantially as described. 10

9. A new composition of matter, compris- This specification signed andwitnessed ing a. solidified solution intermixed with. this 28th day ofDecember 1911.

5 crystals, the ingredients of which composi- JONAS W. AYLSWORTH.

tion comprise a, fusible hydro-carbon-oil- Witnesses: proof gum, acrystalline body of high melt- DYER SMITH,

ing point and only slight solubility in hy- HENRY SHELDON.

